Treatment of joint conditions

ABSTRACT

The invention provides a method of treating a joint condition. The method comprises administering a multi-dose regimen of a pharmaceutical composition comprising a diketopiperazine with amino acid side chains of aspartic acid and alanine (DA-DKP). The invention also provides a method of treating osteoarthritis with multiple doses of a low-molecular weight fraction of human serum albumin.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 16/416,710, filed May 20, 2019; which is a continuation of U.S. patent application Ser. No. 15/933,016, filed Mar. 22, 2018, now issued U.S. Pat. No. 10,342,793; which is a continuation of U.S. application Ser. No. 14/829,289, filed Aug. 18, 2015, now issued U.S. Pat. No. 9,956,217; which claims the benefit of U.S. Provisional Application No. 62/038,682, filed Aug. 18, 2014; the entirety of each of which is hereby incorporated by reference.

FIELD OF INVENTION

The invention relates to a method of treating a joint condition. The method comprises administering an effective amount of a pharmaceutical composition comprising a diketopiperazine with amino acid side chains of aspartic acid and alanine (DA-DKP). The invention also provides the use of a pharmaceutical product comprising DA-DKP.

BACKGROUND

Osteoarthritis is the most common form of arthritis, affecting 25 to 35 million people in the U.S. Chronic pain and disability of osteoarthritis is initially caused by inflammatory responses in joint cartilage and bone that gradually worsens over time. Symptomatic osteoarthritis of the knee occurs in 10 to 13% of persons aged 60 and over. Knee osteoarthritis alone increases the risk of loss of mobility, such as needing assistance walking or climbing stairs, greater than for any other medical condition in people aged 65 and over.

Current drug treatment for osteoarthritis of the knee is limited to analgesics, non-steroidal anti-inflammatory drugs (NSAIDs) and intra-articular steroid injections, all of which have significant limitations due to adverse effects. Despite these medical treatments, chronic knee osteoarthritis often causes progressive disability requiring total joint replacement. The increasing prevalence of osteoarthritis of the knee due to aging and obese populations suggests a growing clinical need for safe and effective local knee treatments that will delay and potentially eliminate the need for more extensive surgical treatments.

SUMMARY OF INVENTION

One embodiment of the present invention is a method of treating a joint condition by administering to an animal in need treatment an effective amount of a pharmaceutical composition that includes DA-DKP in a multi-dose regimen. The joint condition can be a joint disease, such as a degenerative joint disease, for example osteoarthritis. Alternatively, the joint condition can be a joint injury, such as a traumatic injury, a post-operative injury or a repetitive strain injury. Further, the joint condition can be inflammation.

In the method, the composition can be administered by local administration, topical administration, or injection, such as intra-articular injection. If administered by intra-articular injection, the composition can have a concentration of DA-DKP from about 50 μM to about 350 μM.

In the method, the composition can further comprise N-acetyl-tryptophan (NAT), caprylic acid, caprylate or combinations thereof. In this embodiment, the composition can have a concentration of NAT, caprylic acid, caprylate or combinations thereof from about 4 mM to about 20 mM. In a further embodiment, the DA-DKP can be in a composition prepared by removing albumin from a solution of a human serum albumin composition, such as by treating a human serum albumin composition by a separation method selected from ultrafiltration, sucrose gradient centrifugation, chromatography, salt precipitation, and sonication. In a particular embodiment, the step of removing can include passing a human serum albumin composition over an ultrafiltration membrane with a molecular weight cut off that retains the albumin, and wherein the resulting filtrate comprises DA-DKP, such as by use of an ultrafiltration membrane that has a molecular weight cutoff of less than 50 kDa, less than 40 kDa, less than 30 kDa, less than 20 kDa, less than 10 kDa, less than 5 kDa or less than 3 kDa.

In a further embodiment, the pharmaceutical composition can further include a second drug selected from an analgesic, an anti-inflammatory drug, and combinations thereof.

In the method, the number of doses in the multi-dose regimen can be between 2 and 10, between 2 and 8, between 2 and 6, between 2 and 4 or be 3. Further, the time between doses can be between 2 days and 6 weeks between 2 days and 5 weeks, between 2 days and 4 weeks, between 2 days and 3 weeks, between 1 week and 3 weeks, or 2 weeks.

In a preferred embodiment, the present invention is a method of treating osteoarthritis by administering, via intra-articular injection into an affected joint, a first dose, a second dose, and a third dose. In this embodiment, each of the first dose, the second dose, and the third dose comprises 4 mL of a<50001\4W fraction of human serum albumin, and further, the second dose is administered two weeks after the first dose and the third dose is administered two weeks after the second dose.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows the mean percent change in WOMAC A pain score for the treatment described in Example 2.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a method of treating a joint condition by administering a composition comprising DA-DKP in a multi-dose regimen. The treatment comprises administering an effective amount of a pharmaceutical composition comprising aspartyl-alanyl diketopiperazine (DA-DKP) to an individual having a need thereof. DA-DKP has multiple anti-inflammatory and immune modulating effects including inhibition of multiple pro-inflammatory cytokines, chemokines and signaling molecules at the transcription level, inhibition of the migration and adhesion of T-cells and monocytes, activity at the G-coupled protein receptor level, activity on actin-dependent cytoskeletal events, reduction in vascular permeability and inhibition of inflammation induced by platelet activating factor. As described in more detail below, the effects of DA-DKP on joint conditions have been found to be unexpectedly long lasting and in some studies were found to increase in time as compared to the use of steroids.

The invention also provides for a pharmaceutical product comprising a DA-DKP composition. The DA-DKP of the product can be prepared by removing albumin from a solution of human serum albumin.

As used herein, the term “joint condition” refers to any disease, illness, or injury of a joint. Examples of joint conditions include, but are not limited to, acute diseases, chronic diseases, refractory diseases, progressive diseases (including degenerative diseases), traumatic injuries, repetitive strain injuries, toxic injuries, post-operative conditions, and inflammation with or without structural damage.

A degenerative joint disease is a gradual deterioration of the articular cartilage that covers joints. A degenerative joint disease (osteoarthritis) is a noninfectious progressive disorder of the weightbearing joints. The normal articular joint cartilage is smooth, white, and translucent. It is composed of cartilage cells (chondrocytes) imbedded in a sponge-like matrix made of collagen, protein polysaccharides, and water. With early primary arthritis, the cartilage becomes yellow and opaque with localized areas of softening and roughening of the surfaces. As degeneration progresses, the soft areas become cracked and worn, exposing bone under the cartilage. The bone then begins to remodel and increase in density while any remaining cartilage begins to fray. Eventually, osteophytes (spurs of new bone) covered by cartilage form at the edge of the joint. As mechanical wear increases, the cartilage needs repairing. The cartilage cells are unable to produce enough of the sponge-like matrix and therefore the damaged cartilage cannot repair itself. The cartilage has no blood supply to enhance healing. The majority of degenerative joint disease is the result of mechanical instabilities or aging changes within the joint. This includes old age degenerative arthritis and, in younger individuals, may be the result of injuries, bruises, abnormal joint configuration (i.e. hip dysplasia), or mechanical wear from anterior cruciate ligament rupture, patellar luxation, or osteochondritis dissecans, for example. Degenerative joint disease can occur at any joint in the body, including without limitation, knee, hip, shoulder, hand and spine.

Conventional pharmaceutical therapies for joint conditions include acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDS), narcotics, and corticosteroids.

“Treat” is used herein to mean to reduce (wholly or partially) the symptoms, duration or severity of a condition.

The pharmaceutical composition comprising DA-DKP of the invention is administered to an animal in need of treatment. Preferably, the animal is a mammal, such as a rabbit, goat, dog, cat, horse or human. Effective dosage amounts can vary with the severity of the disease or condition, the route(s) of administration, the duration of the treatment, the identity of any other drugs being administered to the animal, the age, size and species of the animal, and like factors known in the medical and veterinary arts.

The composition of the present invention comprising DA-DKP may be administered to an animal patient for therapy by any suitable route of administration, including locally, parenterally (e.g., injection, intra-articular injection, intravenously, intraspinally, intraperitoneally, subcutaneously, or intramuscularly), transdermally, and topically. A preferred route of administration is intra-articular injection.

The composition of the present invention can be a pharmaceutical solution having a DA-DKP concentration range with a lower endpoint of about 10 about 20 about 30 about 40 about 50 about 60 about 70 about 80 about 90 about 100 μM, about 110 μM, about 120 μM, about 130 μM, about 140 μM, about 150 μM, about 160 μM, about 170 μM, about 180 μM, about 190 μM, about 200 μM, about 210 μM, about 220 μM, about 230 μM, about 240 μM, about 240, about 250 μM, about 260 μM, about 270 μM, about 280 μM, about 290 μM, about 300 μM, about 310, about 320 μM, about 330 μM, about 340 μM, about 350 μM, about 360 μM, about 370 μM, about 380 μM, about 390 μM, or about 400 μM. The composition of the present invention can be a pharmaceutical solution having a DA-DKP concentration range with an upper endpoint of about 600 μM, about 580 μM, about 570 μM, about 560 μM, about 550 μM, about 540 μM, about 530 μM, about 520 μM, about 510 μM, about 500 μM, about 490 μM, about 480 μM, about 470 μM, about 460 μM, about 450 μM, about 440 μM, about 430 μM, about 420 μM, about 410 μM, about 400 μM, about 390 μM, about 380 μM, about 370 μM, about 360 μM, about 350, about 340 μM, about 330 μM, about 320 μM, about 310 μM, about 300 μM, about 290 μM, about 280, about 270 μM, about 260 μM, about 250 μM, about 240 μM, about 230 μM, about 220 μM, about 210 μM, or about 200 μM.

An effective amount of DA-DKP in the composition of the present invention for treating a joint condition can be a range with a lower endpoint of about 10 μg, about 15 μg, about 20 μg, about 25 μg, about 30 μg, about 35 μg, about 40 μg, about 45 μg, about 50 μg, about 55 μg, about 60 μg, about 65 μg, about 70 μg, about 75 μg, about 80 μg, about 85 μg, about 90 μg, about 95 μg, about 100 μg, about 110 μg, about 120 μg, about 130 μg, about 140 μg, about 150 μg, about 160 μg, about 170 μg, about 180 μg, about 190 μg, about 200 μg, about 210 μg, about 220 μg, about 230 μg, about 240 μg, about 250 μg, about 260 μg, about 270 μg, about 280 μg, about 290 μg, about 300 μg, about 310 μg, about 320 μg, about 330 μg, about 340 μg, about 350 μg, about 360 μg, about 370 μg, about 380 μg, about 390 μg, about 400 μg, about 425 μg, about 450 μg, about 475 μg or about 500 μg. In addition, an effective amount of DA-DKP in the composition of the present invention for treating a joint condition can be a range with upper endpoint of about 500 μg, about 490 μg, about 480 μg, about 470 μg, about 460 μg, about 450 μg, about 440 μg, about 430 μg, about 420 μg, about 410 μg, about 400 μg, about 390 μg, about 380 μg, about 370 μg, about 360 μg, about 350 μg, about 340 μg, about 330 μg, about 320 μg, about 310 μg, about 300 μg, about 290 μg, about 280 μg, about 270 μg, about 260 μg, about 250 μg, about 240 μg, about 230 μg, about 220 μg, about 210 μg, about 200 μg, about 190 μg, about 180 μg, about 170 μg, about 160 μg, about 150 μg, about 140 μg, about 130 μg, about 120 μg, about 110 μg, about 100 μg, about 90 μg, about 80 μg, about 70 μg, about 60 μg, about 50 μg, about 40 μg, about 30 μg, or about 20 μg.

In embodiments where DA-DKP is administered and a low molecular weight fraction of human serum albumin, such as a<5000 MW fraction as described below and as is exemplified by Ampion™, the dose amount administered to a patient can be between about 1 mL and about 20 mL, between about 1 mL and about 15 mL, between about 1 mL and about 10 mL, between about 1 mL and about 8 mL, between about 2 mL and about 6 mL, between about 3 mL and about 5 mL or about 4 mL.

Dosage forms for the topical or transdermal administration of compounds of the invention include powders, sprays, ointments, pastes, creams, lotions, gels, solutions, patches, and drops. The active ingredient may be mixed under sterile conditions with a pharmaceutically-acceptable carrier, and with any buffers, or propellants which may be required. The ointments, pastes, creams and gels may contain, in addition to the active ingredient, excipients, such as animal and vegetable fats, oils, waxes, paraffins, starch, tragacanth, cellulose derivatives, polyethylene glycols, silicones, bentonites, silicic acid, talc and zinc oxide, or mixtures thereof. Powders and sprays can contain, in addition to the active ingredient, excipients such as lactose, talc, silicic acid, aluminum hydroxide, calcium silicates and polyamide powder or mixtures of these substances. Sprays can additionally contain customary propellants such as chlorofluorohydrocarbons and volatile unsubstituted hydrocarbons, such as butane and propane.

Transdermal patches have the added advantage of providing controlled delivery of compounds of the invention to the body. Such dosage forms can be made by dissolving, dispersing or otherwise incorporating one or more compounds of the invention in a proper medium, such as an elastomeric matrix material. Absorption enhancers can also be used to increase the flux of the compound across the skin. The rate of such flux can be controlled by either providing a rate-controlling membrane or dispersing the compound in a polymer matrix or gel.

Pharmaceutical compositions of this invention suitable for parenteral administrations comprise one or more compounds of the invention in combination with one or more pharmaceutically-acceptable sterile isotonic aqueous or non-aqueous solutions, dispersions, suspensions or emulsions, or sterile powders which may be reconstituted into sterile injectable solutions or dispersions just prior to use, which may contain antioxidants, buffers, solutes which render the formulation isotonic with the blood of the intended recipient or suspending or thickening agents.

Examples of suitable aqueous and nonaqueous carriers which may be employed in the pharmaceutical compositions of the invention include water, ethanol, polyols (such as glycerol, propylene glycol, polyethylene glycol, and the like), and suitable mixtures thereof, vegetable oils, such as olive oil, and injectable organic esters, such as ethyl oleate. Proper fluidity can be maintained, for example, by the use of coating materials, such as lecithin, by the maintenance of the required particle size in the case of dispersions, and by the use of surfactants.

These compositions may also contain adjuvants such as wetting agents, emulsifying agents and dispersing agents. It may also be desirable to include isotonic agents, such as sugars, sodium chloride, and the like in the compositions. In addition, prolonged absorption of the injectable pharmaceutical form may be brought about by the inclusion of agents which delay absorption such as aluminum monosterate and gelatin.

In some cases, in order to prolong the effect of a drug, it is desirable to slow the absorption of the drug from subcutaneous or intramuscular injection. This may be accomplished by the use of a liquid suspension of crystalline or amorphous material having poor water solubility. The rate of absorption of the drug then depends upon its rate of dissolution which, in turn, may depend upon crystal size and crystalline form. Alternatively, delayed absorption of a parenterally-administered drug is accomplished by dissolving or suspending the drug in an oil vehicle.

Injectable depot forms are made by forming microencapsule matrices of the drug in biodegradable polymers such as polylactide-polyglycolide. Depending on the ratio of drug to polymer, and the nature of the particular polymer employed, the rate of drug release can be controlled. Examples of other biodegradable polymers include poly(orthoesters) and poly(anhydrides). Depot injectable formulations are also prepared by entrapping the drug in liposomes or microemulsions which are compatible with body tissue. The injectable materials can be sterilized for example, by filtration through a bacterial-retaining filter.

The formulations may be presented in unit-dose or multi-dose sealed containers, for example, ampoules and vials, and may be stored in a lyophilized condition requiring only the addition of the sterile liquid carrier, for example water for injection, immediately prior to use. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules and tablets of the type described above.

Kits comprising the pharmaceutical products of the present invention are also provided. The kits can comprise a DA-DKP composition formulated for administration by injection. The DA-DKP can be prepared as described herein, such as by removing albumin from a solution of a human albumin composition. The kits may contain unit-dose or multi-dose sealed containers, for example, ampoules and vials, and may be stored in a lyophilized condition requiring only the addition of the sterile liquid carrier, for example water for injection, immediately prior to use. The kits may also be stored in a condition, wherein the contents are ready for direct use or injection.

While it is possible for a compound of the present invention to be administered alone, it is preferable to administer the compound as a pharmaceutical formulation (composition). The pharmaceutical compositions of the invention comprise a compound or compounds of the invention as an active ingredient in admixture with one or more pharmaceutically-acceptable carriers and, optionally, with one or more other compounds, drugs or other materials. Each carrier must be “acceptable” in the sense of being compatible with the other ingredients of the formulation and not injurious to the animal. Pharmaceutically-acceptable carriers are well known in the art. Regardless of the route of administration selected, the compounds of the present invention are formulated into pharmaceutically-acceptable dosage forms by conventional methods known to those of skill in the art. See, e.g., Remington's Pharmaceutical Sciences.

The composition of the present invention can further comprise N-acetyl-tryptophan (NAT), caprylic acid, caprylate or combinations thereof. Preferably, the composition can comprise NAT. Compositions of the present invention having NAT, caprylic acid, caprylate or combinations thereof can be a pharmaceutical composition having NAT, caprylic acid, caprylate or combinations thereof concentration range with a lower endpoint of about 1 mM, about 2 mM, about 3 mM, about 4 mM, about 5 mM, about 6 mM, about 7 mM, about 8 mM, about 9 mM, about 10 mM, about 11 mM, about 12 mM, about 13 mM, about 14 mM, about 15 mM, about 16 mM, about 17 mM, about 18 mM, about 19 mM, or about 20 mM. In addition, compositions of the present invention having NAT, caprylic acid, caprylate or combinations thereof can be a pharmaceutical composition having a NAT, caprylic acid, caprylate or combinations thereof concentration range with an upper endpoint of about 40 mM, about 39 mM, about 38 mM, about 37 mM, about 36 mM, about 35 mM, about 34 mM, about 33 mM, about 32 mM, about 31 mM, about 30 mM, about 29 mM, about 28 mM, about 27 mM, about 26 mM, about 25 mM, about 24 mM, about 23 mM, about 22, or about 21 mM. Preferably, the concentration range is about 4 mM to about 20 mM.

In addition, the composition of the present invention may also comprise a second drug such as an analgesic (such as lidocaine or paracetoamol), an anti-inflammatory (such as bethamethasone, non-steroid anti-inflammatory drugs (NSAIDs), acetaminophen, ibuprofen, naproxen), and/or other suitable drugs.

Methods of making diketopiperazines, such as DA-DKP, are well known in the art, and these methods may be employed to synthesize the diketopiperazines of the invention. See, e.g., U.S. Pat. Nos. 4,694,081, 5,817,751, 5,990,112, 5,932,579 and 6,555,543, U.S. Patent Application Publication Number 2004/0024180, PCT applications WO 96/00391 and WO 97/48685, and Smith et al., Bioorg. Med. Chem. Letters, 8, 2369-2374 (1998), the complete disclosures of which are incorporated herein by reference.

For instance, diketopiperazines, such as DA-DKP, can be prepared by first synthesizing dipeptides. The dipeptides can be synthesized by methods well known in the art using L-amino acids, D-amino acids or a combination of D- and L-amino acids. Preferred are solid-phase peptide synthetic methods. Of course, dipeptides are also available commercially from numerous sources, including DMI Synthesis Ltd., Cardiff, UK (custom synthesis), Sigma-Aldrich, St. Louis, Mo. (primarily custom synthesis), Phoenix Pharmaceuticals, Inc., Belmont, Calif. (custom synthesis), Fisher Scientific (custom synthesis) and Advanced ChemTech, Louisville, Ky.

Once the dipeptide is synthesized or purchased, it is cyclized to form a diketopiperazine. This can be accomplished by a variety of techniques. For example, U.S. Patent Application Publication Number 2004/0024180 describes a method of cyclizing dipeptides. Briefly, the dipeptide is heated in an organic solvent while removing water by distillation. Preferably, the organic solvent is a low-boiling azeotrope with water, such as acetonitrile, allyl alcohol, benzene, benzyl alcohol, n-butanol, 2-butanol, t-butanol, acetic acid butylester, carbon tetrachloride, chlorobenzene chloroform, cyclohexane, 1,2-dichlorethane, diethylacetal, dimethylacetal, acetic acid ethylester, heptane, methylisobutylketone, 3-pentanol, toluene and xylene. The temperature depends on the reaction speed at which the cyclization takes place and on the type of azeotroping agent used. The reaction is preferably carried out at 50-200° C., more preferably 80-150° C. The pH range in which cyclization takes place can be easily determined by the person skilled in the art. It will advantageously be 2-9, preferably 3-7.

When one or both of the amino acids of the dipeptide has, or is derivatized to have, a carboxyl group on its side chain (e.g., aspartic acid or glutamic acid), the dipeptide is preferably cyclized as described in U.S. Pat. No. 6,555,543. Briefly, the dipeptide, with the side-chain carboxyl still protected, is heated under neutral conditions. Typically, the dipeptide will be heated at from about 80° C. to about 180° C., preferably at about 120° C. The solvent will be a neutral solvent. For instance, the solvent may comprise an alcohol (such as butanol, methanol, ethanol, and higher alcohols, but not phenol) and an azeotropic co-solvent (such as toluene, benzene, or xylene). Preferably, the alcohol is butan-2-ol, and the azeotropic co-solvent is toluene. The heating is continued until the reaction is complete, and such times can be determined empirically. Typically, the dipeptide will be cyclized by refluxing it for about 8-24 hours, preferably about 18 hours. Finally, the protecting group is removed from the diketopiperazine. In doing so, the use of strong acids (mineral acids, such as sulfuric or hydrochloric acids), strong bases (alkaline bases, such as potassium hydroxide or sodium hydroxide), and strong reducing agents (e.g., lithium aluminum hydride) should be avoided, in order to maintain the chirality of the final compound.

Dipeptides made on solid phase resins can be cyclized and released from the resin in one step. See, e.g., U.S. Pat. No. 5,817,751. For instance, the resin having an N-alkylated dipeptide attached is suspended in toluene or toluene/ethanol in the presence of acetic acid (e.g., 1%) or triethylamine (e.g., 4%). Typically, basic cyclization conditions are preferred for their faster cyclization times.

Other methods of cyclizing dipeptides and of making diketopiperazines are known in the art and can be used in the preparation of diketopiperazines useful in the practice of the invention. See, e.g., those references listed above. In addition, many diketopiperazines suitable for use in the present invention can be made as described below from proteins and peptides. Further, diketopiperazines for use in the practice of the invention can be obtained commercially from, e.g., DMI Synthesis Ltd., Cardiff, UK (custom synthesis).

The DA-DKP composition and/or products of the present invention can be prepared from solutions containing DA-DKP, including from the commercially-available pharmaceutical compositions comprising albumin, such as human serum albumin, by well known methods, such as ultrafiltration, size-exclusion chromatography, affinity chromatography (e.g., using a column of beads having attached thereto an antibody or antibodies directed to the desired diketopiperazine(s) or an antibody or antibodies directed to the truncated protein or peptide), anion exchange or cation exchange), sucrose gradient centrifugation, chromatography, salt precipitation, or sonication, that will remove some or all of the albumin in the solution. The resultant DA-DKP-containing composition and/or product can be used and incorporated into pharmaceutical compositions as described above.

Using an ultrafiltration separation method, a human serum albumin composition can be passed over an ultrafiltration membrane having a molecular weight cut-off that retains the albumin while the DA-DKP passes into the resulting filtrate or fraction. This filtrate may comprise components having molecular weights less than about 50 kDA, less than about 40 kDa, less than 30 kDa, less than about 20 kDa, less than about 10 kDa, less than about 5 kDa, or less than about 3 kDa. Preferably, the filtrate comprises components having molecular weights less than about 5 Da (also referred to as “<5000 MW”). This <5000 MW fraction or filtrate contains DA-DKP which is formed after the dipeptide aspartate-alanine is cleaved from albumin and subsequently cyclized into the diketopiperazine.

Physiologically-acceptable salts of the DA-DKP of the invention may also be used in the practice of the invention. Physiologically-acceptable salts include conventional non-toxic salts, such as salts derived from inorganic acids (such as hydrochloric, hydrobromic, sulfuric, phosphoric, nitric, and the like), organic acids (such as acetic, propionic, succinic, glycolic, stearic, lactic, malic, tartaric, citric, glutamic, aspartic, benzoic, salicylic, oxalic, ascorbic acid, and the like) or bases (such as the hydroxide, carbonate or bicarbonate of a pharmaceutically-acceptable metal cation or organic cations derived from N,N-dibenzylethylenediamine, D-glucosamine, or ethylenediamine). The salts are prepared in a conventional manner, e.g., by neutralizing the free base form of the compound with an acid.

The present invention involves a method of treating a joint condition that includes administering to an animal in need thereof an effective amount of a pharmaceutical composition comprising DA-DKP in a multi-dose regimen. It has been surprisingly found that significant improvements in pain reduction and improved function can be achieved by the use of a multi-dose regimen to administer pharmaceutical compositions of the present invention as compared to a single dose regimen. U.S. Pat. No. 8,980,834 to Bar-Or et al. (“Bar-Or”), assigned to Ampio Pharmaceuticals, Inc., discloses the treatment of osteoarthritis by injection of a<5000 MW fraction of human serum albumin (referred to as Ampion™). Bar-Or does not disclose a multi-dose regimen and in fact, suggests that because of the long lasting effect of the treatment, single dose administration is sufficient for time periods up to six months. Without intending to be bound by theory, the improved effect of a multi-dose regimen is believed to be achieved by more than a simple increase in the amount of active composition being administered. As shown below in Example 1, no benefit was seen by increasing a single dose administration from 4 mL of Ampion™ to 10 mL. However, when three 4 mL doses of Ampion™ (total of 12 mL) are administered two weeks apart, a significant benefit was seen as shown in Example 2. Thus, there is believed to be at least some effect achieved by prolonging exposure of the joint to the treatment by the extended multi-dose regimen that is independent of the total amount of active composition being administered.

A multi-dose regimen refers to administration of pharmaceutical compositions of the present invention to a patient in multiple doses that are spread apart in time. Two important variables within a multi-dose regimen are the number of doses and the timing between doses. In the present invention, the number of doses is more than two and can be from 2 to 10, from 2 to 8, from 2 to 6, from 2 to 4, or 3. In the present invention, the timing between any two doses can be from 2 days to 6 weeks, from 2 days to 5 weeks, from 2 days to 4 weeks, from 2 days to 3 weeks, from 1 week to 2 weeks, or can be about 2 weeks.

The present invention can provide significant improvements in pain from joint conditions such as osteoarthritis and particularly in the knee joint, as compared to single administration of the treatment. Pain can be evaluated on a number scales and one suitable pain scale is WOMAC A. The present invention can improve WOMAC A scores or other pain scales by 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% over baseline scores.

This embodiment of the present invention can provide significant improvements in joint function and particularly function of the knee joint. Function of joints can be evaluated on a number scales and one suitable scale is WOMAC C. The present invention can improve WOMAC C scores or other joint function scales by 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% over baseline scores.

As used herein, “a” or “an” means one or more.

As used herein, “comprises” and “comprising” include within their scope all narrower terms, such as “consisting essentially of” and “consisting of” as alternative embodiments of the present invention characterized herein by “comprises” or “comprising”. In regard to use of “consisting essentially of”, this phrase limits the scope of a claim to the specified steps and materials and those that do not materially affect the basic and novel characteristics of the invention disclosed herein.

Additional objects, advantages and novel features of the present invention will become apparent to those skilled in the art by consideration of the following non-limiting examples. The following experimental results are provided for purposes of illustration and are not intended to limit the scope of the invention.

EXAMPLES Example 1

A randomized, placebo-controlled, double-blind study was performed to evaluate the efficacy and safety of two doses of intra-articular (IA) injection of Ampion™ in adults with pain due to osteoarthritis of the knee (OAK).

Primary Objective

To evaluate whether the efficacy of 10 mL Ampion™ versus 10 mL placebo is greater than the efficacy of 4 mL Ampion™ versus 4 mL placebo IA injection in improving knee pain, when administered to patients suffering from OAK.

Study Subjects

Study subjects were male and female adult patients who were 40 years to 85 years old (inclusive). Eligible patients were ambulatory but suffering from moderate to moderately severe pain from OAK in the index knee, as evidenced by a rating of at least 1.5 on the WOMAC Index 3.1, five-point Likert Pain Subscale at screening. Patients must have had an index knee that was symptomatic for greater than six months with a clinical diagnosis of OAK, which was supported by radiological evidence (Kellgren-Lawrence (KG) Grade 2 to 4) obtained no more than six months prior to screening. Patients were also required to have moderate to moderately severe OAK pain in the index knee even with chronic dosing of NSAID in the four weeks prior to screening. Patients could not have taken analgesia (including acetaminophen) for twelve hours prior to an efficacy measure.

Treatments

The test product was Ampion™, 4 mL or 10 mL, administered as a single IA injection in the knee. The control product was saline placebo, 4 mL or 10 mL, administered as a single IA injection in the knee. Patients who met the study entry criteria were randomly assigned in a 1:1:1:1 ratio to the following four study arms: 4 mL Ampion™, 4 mL placebo, 10 mL Ampion™, and 10 mL placebo.

The clinical effects of treatment on OAK pain were evaluated using the WOMAC and the Patient's Global Assessment (PGA) at office visits at six and twelve weeks, and optionally at twenty weeks, and during telephone contacts at two, four, eight, and ten weeks. The total duration of the study was twelve weeks, optionally up to twenty weeks, excluding the screening period of up to four weeks before Day 0.

Primary Efficacy Endpoint

The primary efficacy endpoint of this study was the change in the WOMAC A pain subscore on the five-point Likert scale between baseline (Day 0) and Week 12.

Secondary Efficacy Endpoints

The secondary efficacy endpoints of this study were:

-   -   Change in WOMAC A pain subscore between baseline and Weeks 2, 4,         6, 8, and 10, and optionally Week 20;     -   Change in WOMAC B stiffness subscore between baseline and Weeks         2, 4, 6, 8, 10, and 12;     -   Change in WOMAC C physical function subscore between baseline         and Weeks 2, 4, 6, 8, 10, and 12, and optionally Week 20;     -   Change in PGA between baseline and Weeks 6, 8, 10, and 12, and         optionally Week 20;     -   Response status based on the OMERACT-OARSI criteria at Weeks 2,         4, 6, 8, 10, and 12;     -   Change in WOMAC A pain subscore average of questions 1 and 2         (pain with movement) between baseline and Weeks 2, 4, 6, 8, 10,         and 12;     -   Change in WOMAC A pain subscore average of questions 3 through 5         (pain during rest) between baseline and Weeks 2, 4, 6, 8, 10,         and 12;     -   Use of rescue analgesia (amount of acetaminophen used); and     -   Incidence and severity of TEAEs.

Safety Assessments

Safety assessments included collection of concomitant medication data, physical examinations, vital sign measurements, clinical laboratory measurements, and monitoring of TEAEs.

Demographic and Baseline Characteristics

The study population was representative of the population that would be expected to receive treatment with Ampion™. Baseline characteristics were similar across treatment groups: the majority of patients in each group were White and female, and had a median age of approximately 62 years.

Efficacy Results

Subjects receiving Ampion™ achieved significantly greater reduction in WOMAC A pain subscores (improvement) from baseline to Week 12 compared with those receiving placebo (P=0.0038), representing approximately 42% reduction in pain from baseline. Moreover, this improvement in pain was more pronounced in patients with more severe OAK disease; for example, patients with KG Grades 3 and 4 disease had greater improvement in pain compared with placebo at Week 12. Patients receiving Ampion™ also achieved significantly greater improvement in function (WOMAC C) from baseline to Week 12 compared with patients receiving placebo (P=0.04). Additionally, patients receiving Ampion™ also experienced significantly greater improvement in overall quality of life measures, as measured by the PGA, from baseline to Week 12 compared with patients receiving placebo (P=0.01). These clinically and statistically significant improvements in pain, function, and overall quality of life measures were observed after only a single Ampion™ IA injection into the knee.

TABLE 1 WOMAC A pain subscore − mean and change from baseline to Week 12 Randomized Arms Combined Arms Placebo Placebo Ampion Ampion Placebo Ampion 4 mL 10 mL 4 mL 10 mL 4 + 10 mL 4 + 10 mL P- (N = 83) (N = 81) (N = 83) (N = 82) (N = 164) (N = 165) value* BASELINE n 83 81 83 82 164 165 Mean (SD) 2.32 2.23 2.22 2.19 2.27 2.20 (0.548) (0.602) (0.490) (0.512) (0.575) (0.500) Median 2.20 2.00 2.20 2.20 2.20 2.20 IQR 1.80, 2.60 1.80, 2.60 1.80, 2.60 1.80, 2.60 1.80, 2.60 1.80, 2.60 Min, Max 1.4, 4.0 1.0, 3.6 1.2, 3.4 1.2, 3.4 1.0, 4.0 1.2, 3.4 Not Reported 0 0 0 0 0 0 WEEK 12 n 83 81 83 82 164 165 Mean (SD) 1.61 1.50 1.28 1.27 1.55 1.28 (0.759) (0.875) (0.790) (0.764) (0.818) (0.775) Median 1.60 1.60 1.20 1.20 1.60 1.20 IQR 1.00, 2.00 1.00, 2.20 0.60, 2.00 0.80, 1.80 1.00, 2.20 0.60, 2.00 Min, Max 0.2, 3.6 0.0, 3.8 0.0, 2.8 0.0, 3.2 0.0, 3.8 0.0, 3.2 Not Reported 0 0 0 0 0 0 Change (Week 12) n Change 83 81 83 82 164 165 0.0038 Mean Change −0.71 −0.73 −0.93 −0.92 −0.72 −0.93 (SD) (0.752) (0.964) (0.764) (0.791) (0.860) (0.775) 95% CI of −0.871, −0.946, −1.099, −1.093, −0.852, −1.045, Mean Change −0.543 −0.520 −0.766 −0.746 −0.587 −0.807

In the overall group of subjects that attended the Week 20 visit, there was no statistical significance in mean change from baseline in WOMAC A pain subscores; however there was a statistically significant improvement in the KL Grade 4 subset (P=0.036).

TABLE 2 WOMAC A pain subscore in Kellgren-Lawrence (KL) Grade 4 subjects − mean and change from baseline to week 20 Placebo Placebo Ampion Ampion Placebo Ampion P- KL 4 Subset 4 mL 10 mL 4 mL 10 mL 4 mL + 10 mL 4 mL + 10 mL value BASELINE (Randomization) n 45 44 52 52 89 104 Mean (SD) 2.28 2.22 2.16 2.22 2.25 2.19 (0.552) (0.546) (0.474) (0.501) (0.547) (0.486) Median 2.20 2.20 2.00 2.20 2.20 2.20 IQR 1.80, 1.80, 1.80, 2.00, 1.80, 1.80, 2.60 2.50 2.60 2.60 2.60 2.60 Min, Max 1.6, 4.0 1.6, 3.6 1.2, 3.4 1.2, 3.4 1.6, 4.0 1.2, 3.4 Not Reported 0 0 0 0 0 0 WEEK 20 n 14 13 11 10 27 21 Mean (SD) 1.89 1.92 1.22 1.70 1.90 1.45 (0.655) (0.630) (0.855) (0.492) (0.631) (0.732) Median 1.90 2.00 1.00 1.70 2.00 1.40 IQR 1.20, 1.80, 0.60, 1.20, 1.20, 1.00, 2.40 2.40 2.00 2.20 2.40 2.00 Min, Max 0.8, 2.8 0.6, 3.0 0.2, 2.6 1.0, 2.4 0.6, 3.0 0.2, 2.6 Not Reported 0 0 0 0 0 0 Change (Week 20) n Change 14 13 11 10 27 21 Mean Change −0.69 −0.32 −1.09 −0.32 −0.51 −0.72 0.0360 (SD) (0.713) (0.893) (1.104) (0.598) (0.810) (0.962) 95% CI of −1.098, −0.863, −1.833, −0.748, −0.832, −1.162, Mean Change −0.274 0.216 −0.349 0.108 −0.191 −0.286

Conclusions

The results of this study establish the safety and efficacy of Ampion™ for reduction of pain at twelve weeks after a single IA injection in the knee of patients with OAK. Both 4 mL and 10 mL doses of Ampion™ are safe, efficacious, and well tolerated. In the absence of a difference in efficacy for the 4 mL and 10 mL Ampion™ doses, the lower dose of 4 mL was to be evaluated in further studies. The reduction in the mean WOMAC A pain subscore of KL Grade 4 patients in the combined 4 mL and 10 mL arms at 20 weeks was about 34%. In the overall group of patients evaluated at week 20, including patients in addition to KL Grade 4, there was no statistically significant change.

Example 2

A prospective Phase I/II study was performed to evaluate the safety and efficacy of three intra-articular injections of Ampion™ (4 mL) administered two weeks apart in adults with pain due to osteoarthritis of the knee.

Primary Objectives

The primary objective of Phase I was to evaluate the safety of Ampion™ 4 mL administered as three IA injections, two weeks apart, in patients suffering from OAK of the knee from baseline to Week 20.

The primary objective of Phase II was to evaluate the safety and efficacy of Ampion™ 4 mL versus placebo injection from baseline to Week 20, when administered as 3 IA injections, in improving knee pain in patients suffering from OAK of the knee.

Study Subjects

For both the Phase I and Phase II studies, subjects were male and female adult patients who were 40 years to 85 years old (inclusive) with OAK knee pain. Eligible patients were required to be ambulatory and the index knee must have been symptomatic for greater than six months with a clinical diagnosis of OAK supported by radiological evidence (KL Grades 2 to 4) acquired at screening. Patients must have had moderate to moderately severe OAK pain in the index knee (rating of at least 1.5 on the WOMAC Index 3.1 five-point Likert Pain Subscale) assessed at screening and confirmed at randomization. The moderate to moderately severe OAK pain in the index knee must have been present even if chronic doses of NSAIDs, which had not changed in the four weeks prior to screening, had been or were being used. Patients could not have taken analgesia for twelve hours prior to an efficacy measure. It was recommended that patients should have a WOMAC five-point Likert Pain Subscale score of less than 1.5 in the contralateral knee, which was assessed at screening.

In Phase I, a total of seven patients were to be enrolled, and enrollment of KL Grade 2 patients was limited to no more than two patients. The medical monitor conducted a safety evaluation after all seven patients had completed the Week 4 follow-up evaluation. Enrollment was to be initiated in Phase II if no serious drug-related AEs or unanticipated drug-related AEs were observed. Pending safety review, the seven patients were to continue in the Phase I study until Week 52.

In Phase II, approximately forty patients were to be enrolled and randomized 1:1 across the two study arms (twenty patients per study arm). Enrollment of KL Grade 2 patients was limited to 25% of total enrollment in Phase II, i.e. eight patients total, randomized 1:1 across the two study arms.

Treatments

The test product for both Phase I and Phase II was Ampion™, and the control product for the Phase II study was saline placebo.

For Phase I, patients who met the study entry criteria received three IA injections of 4 mL Ampion™ in the knee at baseline (Day 0) and at Weeks 2 and 4. For Phase II, patients who met the study entry criteria were randomly assigned in a 1:1 ratio to the 4 mL Ampion™ study arm or the 4 mL placebo study arm. Subjects received three IA injections in the knee of study medication (Ampion™ or placebo) at baseline (Day 0) and at Weeks 2 and 4.

Subjects attended in-clinic visits at Week 6, Week 12, Week 20, Week 24, and Week 52. The maximum study duration for each patient was 52 weeks, excluding a screening period of up to four weeks.

Endpoints

In Phase I, the incidence and severity of TEAEs and SAEs was determined.

The primary efficacy endpoint of Phase II was the change in the WOMAC A pain subscore by the five-point Likert scale from baseline (Day 0) to Week 20. Secondary endpoints of Phase II were:

-   -   Change in WOMAC A pain subscore from baseline (Day 0) to Weeks         2, 4, 6, 12, 24, and 52;     -   Change in WOMAC C physical function subscore from baseline         (Day 0) to Weeks 2, 4, 6, 12, 20, 24, and 52;     -   Change in PGA from baseline (Day 0) to Weeks 2, 4, 6, 12, 20,         24, and 52;     -   Use of rescue analgesia (amount of acetaminophen used) through         Week 20; and     -   Incidence and severity of TEAEs

Safety Assessments

Safety assessments included recording TEAEs at all in-clinic visits and the 24-hour post-injection telephone contact calls; physical examination and vital sign recordings at in-clinic visits at baseline (Day 0) and at Weeks 2, 4, 6, 12, 20, 24, and 52); and standard laboratory tests.

Exposure

In Phase I, seven subjects were enrolled and received all three injections of Ampion™. In Phase II, forty subjects (twenty Ampion™, twenty placebo) were enrolled and received all three injections of study drug.

Demographic and Baseline Characteristics

Baseline characteristics were similar across treatment groups: the majority of patients in each treatment group were White and female, with a median age of 62.5 years, and had KL Grade 3 (58%) or Grade 4 (38%).

Efficacy Results

Subjects receiving Ampion™ achieved significantly greater reduction in WOMAC A pain subscores (improvement) from baseline to Week 20 compared with those receiving placebo (P=0.0231). This represents a reduction in mean pain of approximately 64% from baseline in the Ampion™ arm compared with a reduction of approximately 40% in the placebo arm (P=0.0313), as illustrated in FIG. 1.

TABLE 3 WOMAC A pain subscore-mean and change form baseline to Week 20 Ampion Placebo 4 mL 4 mL (N = 20) (N = 20) P-value BASELINE N 19 19 Mean (SD) 2.26 (0.46) 2.18 (0.45) Median 2.40 2.20 Min, Max 1.6, 3.0 1.5, 3.0 WEEK 20 N 19 19 0.5960 Mean (SD) 0.85 (0.88) 1.34 (0.73) Median 0.40 1.40 Min, Max 0.0, 3.0 0.0, 2.2 Change (Week 20) N Change 19 19 0.0231 Mean Change (SD) −1.41 (0.81) −0.85 (0.64) 95% CI difference (0.10, 1.03) for Mean Change

Patients receiving Ampion™ demonstrated no significant differences in WOMAC A pain subscore from baseline at Weeks 2, 4, 6, 12, or 24 compared with patients receiving placebo.

Conclusions

The results of this study establish the safety and efficacy of Ampion™ for reduction of pain at twenty weeks after three IA injections, two weeks apart, in the knee of patients with OAK. The 4 mL dose of Ampion™ was safe, efficacious, and well tolerated.

While various embodiments of the present invention have been described in detail, it is apparent that modifications and adaptations of those embodiments will occur to those skilled in the art. It is to be expressly understood, however, that such modifications and adaptations are within the scope of the present invention, as set forth in the following exemplary claims. 

1-33. (canceled)
 34. A method of treating a joint condition comprising administering a composition comprising DA-DKP in a multi-dose regimen.
 35. The method of claim 34, wherein the joint condition is a degenerative joint disease.
 36. The method of claim 35, wherein the degenerative joint disease is osteoarthritis.
 37. The method of claim 34, wherein the joint condition is inflammation.
 38. The method of claim 34, wherein the composition is administered by injection.
 39. The method of claim 34, wherein the concentration of DA-DKP in the composition is selected from about 50 μM to about 350 μM and about 110 μM to about 200 μM.
 40. The method of claim 34, wherein the composition further comprises N-acetyl-tryptophan (NAT), caprylic acid, caprylate or combinations thereof.
 41. The method of claim 40, wherein the concentration of each of NAT, caprylic acid, caprylate or combinations thereof in the composition is independently selected from about 1 mM to about 20 mM and about 1 mM to about 4 mM.
 42. The method of claim 34, wherein the number of doses in the multi-dose regimen is between 2 and 6 doses per 52 weeks.
 43. The method of claim 34, wherein the amount of each dose is between about 2 mL and about 6 mL.
 44. A method of treating osteoarthritis in a joint, comprising administering a composition comprising DA-DKP, N-acetyl-tryptophan (NAT) and caprylate in a multi-dose regimen.
 45. The method of claim 44, wherein the composition is administered by injection.
 46. The method of claim 45, wherein the injection is intra-articular.
 47. The method of claim 44, wherein the concentration of DA-DKP in the composition is selected from about 50 μM to about 350 μM and about 110 μM to about 200 μM.
 48. The method of claim 44, wherein the concentration of each of NAT and caprylate is independently selected from about 1 mM to about 20 mM and about 1 mM to about 4 mM.
 49. The method of claim 44, wherein the number of doses in the multi-dose regimen is between 2 and 6 doses per 52 weeks.
 50. The method of claim 44, wherein the amount of each dose is between about 2 mL and about 6 mL.
 51. The method of claim 50, wherein the amount of each dose is about 4 mL.
 52. The method of claim 44, wherein the osteoarthritis is accompanied with pain.
 53. The method of claim 44, wherein the joint is a knee. 